three-row cylindrical rollers slewing ring bearings made in china

1.Three-row cylindrical rollers slewing ring bearings

Three-row cylindrical rollers slewing ring bearings are the perfect choice for heavy duty bearings. It is also the most stable, reliable and longest life slewing bearing.

The three-row cylindrical roller combined slewing bearing bears axial load, overturning moment and radial load at the same time. Compared with the crossed cylindrical roller slewing bearing, the load of each roller is reduced.

Compared with the double row reducing ball slewing bearing, the point contact is changed to the line contact, which reduces the contact stress. The load carrying capacity is the highest bearing.

The axial load and radial load of the structure are borne by different rollers, wherein the axial load and overturning moment are borne by two sets of rollers with the axis horizontally placed, and the radial load is borne by a set of rollers placed with the axis vertically.

Different raceways and rollers bear, so under the same stress conditions, the diameter of the bearing can be greatly reduced, thus making the host more compact, and it is a slewing bearing with high bearing capacity.

This structural bearing is suitable for occasions with large axial load and overturning moment, large radial load, and low friction torque requirements. Cages are generally made of nylon isolation fast, nylon segmented cages, aluminum alloy cages segmented steel cages and brass cages according to different applications.

Application areas:

Widely used in stacker and reclaimer, overweight transport machinery, port crane, ladle turntable, shield machine and other applications.

The most commonly used structure of slewing bearings, four-point contact ball bearings, including double-row ball bearings, crossed roller bearings, including crossed tapered roller bearings, three-row cylindrical rollers slewing ring bearings, its technical characteristics? What are the technical characteristics, and what kind of bias is there in the selection of working conditions? This article focuses on the discussion.

Generally speaking, four-point contact ball bearings are resistant to permanent fatigue, crossed roller bearings are resistant to permanent deformation, and crossed tapered roller bearings have strong rigidity and high rotational accuracy. The tthree-row cylindrical rollers slewing ring bearings has the same size as the slewing bearing with high load capacity.

Based on this, the characteristics of various structural bearings in the application are obviously different.

What are the characteristics of three-row cylindrical rollers slewing ring bearings? In short, four sentences: 1. The strongest bearing capacity 2. The axial load and eccentric load capacity surpasses other structures, unique 3. The force analysis is obviously optimized 4. The master

But why choose an integral cage? Steel cages and copper cages are the most common. Force analysis and force direction, one is inclined installation, vertical installation and often bear heavy load, to ensure the rolling motion of the ball, the force distribution is even.

In this way, the life and reliability of the bearing are significantly improved after the use of the integral cage. Of course, the cost will increase by at least 30,000 to 100,000 RMB. Compared with safety and reliability, it is still quite worthwhile.

To put it bluntly, the overall cage is to ensure that the rolling elements are in place and operate smoothly and orderly, so that whether it is installed at an inclined angle or installed vertically, it can ensure quality and life.

Three-row cylindrical rollers slewing ring bearings are the ultimate form of construction for low-speed, heavy-duty slewing bearings. In order to ensure the heavy-duty life and reliability of the slewing bearing, the selection of the structural form of the cage is very important. The reference index is the demand of the working condition.

The cage of the three-row roller bearing is usually based on the main thrust roller cage and the auxiliary thrust roller cage, and the radial cage is supplemented by the design idea. There are boxed cages, segmented cages and integral cages. , the cost increases sequentially, and its stability is relatively gradually enhanced.

It should be pointed out that segmented cages and integral cages are more targeted for special working conditions. Boxed cages are only suitable for horizontal installation.

Bulk Truck Crane Slewing Bearing

Slewing Bearing Installation

First of all, compared with other parts, the slewing bearing is the core of the rotating part and belongs to the precision product. Therefore, it is necessary to understand the installation precautions of the slewing bearing:
1. After understanding the rotation accuracy of the slewing bearing, first ensure that the installation base is flat. Remember, it is very important, the base is not flat, and the hidden danger is great.
2. Whether the force and eccentric load of the slewing bearing are within the theoretical calculation
3. According to whether the bolts are installed or not, pre-tighten them into 180° one by one.
4. Whether the S soft belt area is in the non-load area, that is, the area where the force is not often or the weakest force, taking the crane as an example, the bearing should be installed in the area where the cantilever direction is vertical
5. After the gear meshing rotates in the forward and reverse directions, no other abnormal noises can be gnawed.
6. There is a slight noise after the new bearing is installed. After fully refueling, the forward and reverse rotation still cannot eliminate the abnormal noise.
7. The positioning size of the bearing
8. The size of the mouth of the bearing
9. The seal of the bearing must not be interfered with by foreign objects, otherwise the sealing strip will be damaged
10. There should be no interference in the position of the dust baffle

The six dimensions determine the installation effect of the slewing bearing

Regarding the installation of the slewing bearing, there are six core dimensions, which determine the installation effect of the slewing bearing.

1. Dimensions. Including inner diameter, outer diameter, assembly height, and positioning spigot size. If the lip size is not in place, the installation of the slewing bearing will definitely be affected.

2. Positioning hole size. There are generally two or three positioning holes, which determine the position of the slewing bearing.

3. Mounting hole size, including center diameter, chord length, threaded hole, counterbore and lubrication hole.

4. Clearance. Including axial clearance, radial clearance, inclined clearance.

5. Gear size. Including tooth surface roughness, common normal length, gear highest point, as well as modulus, displacement coefficient, and tooth jump.

6. Tolerance dimensions, end runout, radial runout, and tooth runout.

What factors will cause the installation of the slewing bearing to be unsmooth or even unable to rotate? Taking the following factors into consideration,

1. Mounting holes. The threaded hole of the mounting hole is not standardized, the threading is not complete, and the threading is defective, so that the bolt cannot be screwed in.

2. The center diameter and chord length of the mounting hole exceed the tolerance too much, such as 3-5mm, so that the bolt cannot be pierced

3. The size of the positioning hole and the step is too large and cannot be matched

4. The bearing after heavy load has a rotating dead center or an ellipse, which causes it to fail to operate normally.

5. The bearing is not in the installation direction of the installation design drawing, resulting in the opposite direction of the taper pin, which has potential safety hazards

6. The installation part interferes, such as tooth top interference, there is a phenomenon of gnawing teeth, and some parts conflict with each other

7. The design of negative clearance is unreasonable, resulting in the phenomenon of inclined force, partial load and clearance after installation

8. The design of the equipment structure is unreasonable, which leads to the failure of normal debugging.

Slewing Ring Bearing For Sale

1.Installation of large slewing ring bearings

1 Disposal of slewing ring bearing maintenance

1.1 Anti-rust and packaging

The inner and outer surfaces of the slewing ring bearing are evenly coated with anti-rust and lubricating oil on both sides of the bearing, and the packaging is wrapped with plastic film kraft paper and linen strips. The outer surface of the large-size slewing bearing should also be wrapped with plastic cloth. For small size slewing bearings, use wooden boxes.

1.2 Warehousing

Regardless of whether it is a new bearing or a slewing bearing that is maintained or repaired, the parts need to be individually rust-proof and lubricated. The whole piece needs to be maintained in accordance with the standard of JB/T10471, including the accuracy of the bearing, horizontal placement, dust-proof, and lubrication. During the stacking period, it is strictly forbidden to tilt, place under heavy pressure, and place in the open air. The principle of storage allowable time is 10 months. The packaging adopts three layers of protection. After adding grease, the appearance is rust-proof. Film, kraft paper, foam padding, plus wrapping tape.

transportation

Keep the bearings as horizontal as possible during transportation, only allow a slight tilt, and avoid large bumps or vibrations. After unpacking, screw the lifting bolt into the lifting hole of the inner ring or outer ring to transport the bearing to the installation position.

1.3 Safekeeping

1.3.1 In the rust-proof period before use (within 12 months after the bearing leaves the factory). Do not open the package. If maintenance is required, the raceway, outer surface and tooth surface of the slewing bearing should be treated with anti-rust treatment.

1.3.2 Lay it horizontally on a dry and flat site.

1.3.3 If the slewing bearing is stored for more than 12 months, it should be re-rusted.

1.3.4 If multiple sets of slewing bearings are stacked together, at least three evenly distributed wooden pads should be placed between each set of slewing ring bearings along the circumferential direction, and the upper and lower pads should be placed in the same position.

2 Installation of slewing bearing

2.1 Preparation before installation

2.1.1 The connecting surfaces of the supporting parts shall be machined, and then these surfaces shall be free of burrs and debris.

2.1.2 When the radial load exceeds 10% of the axial load, there should be radial positioning, and the connecting surface that cannot be machined should be flattened by injection molding.

2.1.3 When unpacking the bearing before installation, care should be taken to avoid damage to the seal and prevent dust from entering the inside of the bearing. Within the specified anti-rust period, it is not necessary to disassemble and clean before installation.

2.2 Soft belt position

The quenched soft tape of the slewing bearing ring is marked “S”. When installing, the position of the soft belt should be in the non-loading area or the non-recurrent load area (the filling plug is always located at the soft belt of the ferrule.)

2.3 Ring gear inspection

Before the mounting bolts are not fully tightened, the gear meshing check should be carried out to ensure that the meshing clearance and the accuracy requirements of the gears are met.

2.4 Tightening of mounting bolts

When installing bolts, quenched and tempered flat washers can be used, and spring washers are prohibited.

After locating the slewing bearing radially, tighten the mounting bolts crosswise and check the free rotation of the bearing at the same time.

There should be sufficient pre-tightening force when tightening the bolt, and its pre-tightening force should be 70% of the yield limit of the bolt material.

3 Use and maintenance

3.1 Inspection of mounting bolts and abnormal phenomena

After about 100 hours of operation of the slewing bearing, check the pre-tightening torque of the mounting bolts of the inner ring and the outer ring, and every 500 hours of operation thereafter.

If there are abnormal phenomena such as noise, impact, and sudden increase in power during use, it should be shut down for inspection.

3.2 Lubrication

After the slewing bearing is installed, it should be filled with suitable grease according to the actual use conditions, and the slewing bearing should be filled while the grease is evenly distributed until the new grease begins to squeeze out of the sealing lip. Fill it every 50~100 hours, and the oiling cycle should be shorter in high environment and dusty conditions. New grease must also be added before and after the machine has been stopped for a long time.

3.3 Cleaning and assembly of slewing bearing

In the assembled slewing bearing, the parts between sleeves and between rows and between rows are not interchangeable. When the bearing is disassembled and cleaned, it should be carried out according to the bearing assembly drawing, and the upper and lower half rings should be assembled according to the original drilling position.

The tooth surface should be cleaned of debris every 10 days and coated with grease.

3.4 Selection of Grease

For the lubrication of the slewing bearing, because there are many comprehensive working factors, the user can choose the best grease according to the specific requirements.

Industrial Positioners Slewing Bearing In Stock

1.slewing bearing

Due to its reliable performance, stable operation, large rotation angle, easy control and high working efficiency, bucket turbines are widely used in large power plants and transshipment terminals.

Therefore, the slewing bearing plays a key role in the working process of the bucket turbine, but in the long-term working process of the bucket turbine, it not only has a large working load, but also wears the slewing bearing seriously for long-term use, which affects the bucket wheel. Therefore, it is necessary to strengthen and optimize the maintenance process of the bucket turbine.

Bucket turbine slewing bearing usage

The slewing bearing signal in this study is the thrust radial crossed roller bearing (model 1797/3230G2K9) produced by Luoyang Bearing Factory. The equipment has a total of 114 rollers (the diameter and height of the column are φ98mm and 97.5mm, respectively) Mainly in the form of cross arrangement.

A total of 12 bucket turbines are used in a centralized manner. After troubleshooting, 6 new bearings 1797/3230G2K4 were purchased and put into use as spare parts.

For a long time, the bucket wheel machine invested by our factory has shouldered an important mission. Since it was put into production in 2008, relevant technical transformations have been arranged, but only routine maintenance and maintenance are carried out. In the process of practice, the main collection of thousands of gas stations

Medium lubrication is the main method, but due to the long and small diameter of the refueling pipeline, it is difficult to ensure the normal smoothness of the oil circuit, and the slewing bearing pipes and rollers cannot be well lubricated. In May 2014, the overhaul of the bucket turbine was arranged, and the lifting inspection of the slewing bearing was an important part.

In this part, the gear passport and the connecting bolt of the bearing were disassembled, and a 100T jack was used to support it. After careful inspection, it was found that the lubrication system was in very poor condition, the sealing condition was poor, and there were residues entering the bearing track.

Analysis of Failure Causes of Slewing Bearings of Bucket Turbines and Measures Taken

The bucket turbine is different from other mechanical equipment. It is large and difficult to move, and the work intensity is relatively high in the transfer work of the power plant and the wharf. The slewing bearing has brought a lot of damage. The slewing bearing must be effectively maintained during the operation of the bucket turbine.

There are probably several reasons for the failure:

(1) The slewing bearing of the bucket turbine has been used for a long time, and there are some small problems in the maintenance process that have not been paid attention to. The accumulation of problems over time will eventually lead to major failures;

(2) During the working process of the bucket turbine, the overhaul and maintenance of the bucket turbine were not timely, so that some minor problems in the working process of the bucket turbine were not reported for maintenance in time, and the maintenance and cleaning of the bucket turbine was not in place, which made the slewing bearing of the bucket turbine. There is a lot of dust inside, which affects the rotation of the bearing and causes the failure of the slewing bearing;

(3) During the transfer process of the bucket wheel machine, the overloaded transfer of goods will damage the working performance of the bucket wheel machine, thereby causing the work failure of the bucket wheel machine.

Analysis on Maintenance Process of Slewing Bearing of Bucket Turbine

For a large and difficult-to-handle mechanical equipment like a bucket wheel, when it breaks down and decides to overhaul it – be sure to make preparations for the overhaul work. The bucket wheel is different from other small mechanical equipment. Good can

Continue the maintenance with extended time, it cannot leave the transfer work for too long, and the transfer work of the power plant and the wharf will face the threat of paralysis, and it is not practical in most cases to introduce a new bucket wheel , so the maintenance time can only be shortened, and the preparations before the maintenance should be done well.

Technical advice:

Explanation of matters needing attention when overhauling bucket turbine slewing bearing

There are some maintenance items that need to be paid attention to during the maintenance process of the bucket turbine. First of all, pay attention to the lubrication effect of the bearing raceway during the maintenance process of the slewing bearing.

For a huge slewing bearing, if the lubrication effect of the narrow and long raceway is not good, not only the dust accumulated in the raceway will affect the operation of the bearing for a long time, and the rolling It is difficult for the lubricating oil added to the raceway to have the desired effect.

In this way, even if the slewing bearing is repaired, when it is put into use, the bearing will be worn again due to the poor lubricating effect of the raceway, which takes a long time. Bearings will also fail, so we must pay attention to the lubrication and cleaning of bearing raceways, pay attention to the method of adding lubricating grease, and minimize bearing wear.

Secondly, in addition to the impact of the lubrication effect of the raceway on the slewing bearing of the bucket turbine, the upper body of the bucket turbine has a deviation in the balance moment, which makes the wear of the bearing in the raceway more serious. Correction of the counterweight to reduce the deviation of the balance moment of the upper body of the bucket turbine.

Finally, pay attention to the installation of the local tempering belts on the inner and outer rings of the bearing. Resolutely do not install the tempering belts on the inner and outer rings in the same way. They must be installed staggered from each other to reduce the bearing capacity of the bearing and reduce the effect of the tempering belt on the bearing operation process. of wear.

Therefore, it is necessary to confirm the model, technical agreement and bearing confirmation drawings in advance, and prepare new large bearings in advance in case of emergency.

Through the explanation of the reasons for the failure of the large-scale slewing bearing of the bucket turbine, the analysis of the maintenance process during the maintenance process, and the precautions during the maintenance, it is known that strengthening the maintenance and maintenance of the large-scale slewing bearing of the bucket turbine in the process of the bucket turbine

It is very important, and for this kind of bulky mechanical equipment, strict maintenance and cleaning work can not only find problems in time and report them to the maintenance personnel for timely maintenance work, but also protect the bucket turbine to a large extent.

The stability of the working performance reduces the failure rate of the bucket wheel. For the maintenance process of the slewing bearing, it can effectively shorten the maintenance time, try to ensure the highest and most stable working performance of the bucket turbine with the lowest maintenance cost, and improve the transfer level of the bucket turbine.

INA Slewing Ring Products

Three factors determine the diameter structure accuracy of the slewing bearing

1. The size of the rotary table, generally, the bearing diameter is controlled at 2/3–1/2 of the rotary table. Such as a four-meter turntable, the diameter of the turntable bearing is 2500-3000.

2. Load and speed

These two factors determine the structure of the INA slewing ring, whether it is a four-point contact ball bearing, a crossed roller bearing, a double-row ball slewing ring, or a three-row roller structure bearing.

3. High speed, high speed and light load are normally recommended, such as four-point contact ball bearings, spacer blocks are conducive to grease lubrication, and integral cages or segmented PTFE cages are conducive to reducing noise and resistance.

4. For low speed and heavy load, choose three-row roller structure INA slewing ring.

5. High-precision bearings, cross-cylindrical cross-tapered roller bearings are easy to implement. However, practice has proved that crossed roller INA slewing rings are not practical in inclined, vertical and multiple motion forms.

6. For slewing bearings with precise pointing, the clearance should be controlled at less than or equal to 0, and for crossed roller bearings and three-row roller structure bearings, it should be controlled at 0-0.03.

2.Lubrication and sealing of slewing bearings

Sealing and lubrication of slewing bearings. Applying effective lubrication and sealing to the slewing bearing is a necessary measure to ensure the safe operation of the bearing and avoid abnormal early damage. There are two ways to lubricate the slewing bearing: oil lubrication and grease lubrication.

Since grease lubrication has a lubricating effect, it has a certain sealing effect. It has the advantages of good adhesion, simple sealing structure, simple operation and low cost, so it is widely used in the actual use of slewing bearings.

The lubrication of the slewing bearing is divided into two parts: the internal lubrication of the bearing and the lubrication of the tooth surface. There are differences in lubricating properties. In actual application, one or two different lubricants are used. When using the same lubricant, any needs of the two should be taken into account. When using two grades or different greases, the compatibility of the lubricant should be considered. .

If the customer has special requirements, the slewing bearing is generally full of lubricating value before delivery to the customer. Before the bearing is used, the customer can base on the actual working conditions of the bearing. Refill the grease again to ensure the life and reliability of the rotary bearing.

The slewing bearing with ring gear has the function of transmitting power and simplifying the host mechanism. Among them, the internal tooth slewing bearing has compact structure, low contact stress during transmission, small wear, grease, easy to maintain lubrication for a long time, good dustproof effect, and the protection requirements for the meshing part are relatively better than the external tooth meshing effect.

External tooth structure slewing bearing, tooth shape processing and detection methods are fast and convenient. High manufacturing precision. It is easy to obtain the highest precision of grinding teeth, and can maximize the use of support space. And the pitch circle diameter of the tooth shape is large. Larger transmission ratios can be obtained.

At the same time, the circumferential force and torque of the pinion can also be reduced, thereby saving efficiency. Of course, in terms of manufacturing cost, the internal teeth are mostly gear shaping, which takes a long time, and the external teeth are mostly gear hobbing, which is fast. Therefore, internal gear bearings are generally much more expensive than external gears.